But when I ran the runIstaller of examples CD, it detected my base home automatically as:/u01/oracle/VIS/db/tech_st/11.2.0 and it can not be updated(not editable).
So I encounter the error:[INS-32052] Oracle base and Oracle home locations are same.

OUI didn't take it.
I set it manually like export ORACLE_BASE=u01/oracle/VIS/db/tech_st
but OUI take the value as /u01/oracle/VIS/db/tech_st/11.2.0.It's wrong!!!
And I can't change it,because it is uneditable!

But when I change the path of SOFTWARE LOCATION,for example /u01/oracle/VIS/db/tech_st/11.2.0a, the textbox of oracle base can be editable.Why?
If I delete the a in SOFTWARE LOCATION,the oracle base changed into /u01/oracle/VIS/db/tech_st/11.2.0 automatically.It's amazing but wrong!

And actually, by default would be '/u01/app/oracle/product/11.2.0/db_1'. The fact that you have set it to be something so different suggests you tried to be smarter than Oracle when you installed the product and created your database.

Let's start from the beginning. Show us the contents of /etc/oraInst.loc.

In that file you should see a line like:

inventory_loc=/u01/app/oraInventory

Take whatever value your file shows as inventory_loc, then within that directory, show us the contents of '../ContentsXML/inventory.xml'

This is an R12 EBS Vision install - hence the structure you see. Why are you trying to install the Examples CD ? Have you sourced the database environment file to set appropriate environment variables ?